Given the rapid pace of change in the market for high-tech goods, there is a need for fast construction, of high-tech plants in order to meet or exceed the production timeline for fabrication of high-tech products such as chips. To expedite manufacturing, precast columns, precast beams and precast waffle slabs are used, so as to save significant time on pouring concrete and binding reinforcement bars at the construction site. Precast waffle slabs are typically used as the flooring of a clean room of a high-tech factory. A clean room designed to maintain positive pressure such that air with contaminants is exhausted via the through holes provided in the precast waffle slabs. The contaminated air is then filtered and returned into the clean room. However, the through holes in the precast waffle slabs are large enough to potentially hinder placement of machines thereon, which require a smooth surface. A conventional approach for solving this problem is placing raised flooring on at least a portion of the precast waffle slab on which the machines are then placed. However, this approach adds cost and time to arrange the clean room. Another conventional approach is to provide slabs without through holes therein and then milling a predetermined quantity of through holes at predetermined areas of the slabs on which the machines are not to be placed. However, such approach will create dust during the milling process, to which workers will be exposed. Moreover, after the completion of the clean room construction, the dust come from the above-mentioned swilling process needs to be removed, which requires additional labor.
In light of the above, it is desirable to find a solution that uses existing precast waffle slabs and also can fully support machines without the defects in the above conventional approaches.